Intake manifold



Aug. 3, 1937. B. A. SWENNES INTAKE MANIFOLD Filed March 24 360CRANKSHAFT REVOLUTION e/nf/errfar:

jay k747i? 360 n CRANKSHAFT REVOLUTION L m e.

Patented Aug. 3, 1937- Benjamin :Arthur-Swennes, Rockford; 111.; as-

. "Signor to "Borg-Warner Corporation, Chicago,

111., a corporation of Illinois Application March 24,

1 t V t v t t isolaims.

- t'll'he invention relatesgenerally to an intake manifold for internalcombustion engines and particularly to 1 an intake manifold for I amulticylinder engine.

5 In multi-cylinder enginespthe cylinders are commonly designated bynumbers runningconsecutively from the front to the rear of the "engine;.For purposes o-fbalance, the=firing order 'of' the cylinders is' not in-consecutiveorder from 1 frontto rear but iscommonly'arranged so that notwo' adjacent cylinders fire -in'-succession. in a six-cylinder engine acommon firing order is1--5-3-6--2-4. The sequence of operation of theintake Valves for the cylinders correspondsto *thesequenceof'firin'gorder of the cylinders andthus requires that acombustible mixture' be supplied first tothe extreme forward'cylinder,thento a cylinder positioned inthe rear of the engine, then 'to-acylinder positioned intermediate the-engine and so on.

1 The "manifolds heretofore -employed to provide a combustible mixtureto the-cylindershave been of a generallyT shaped formation Withahorizontal A portion providing 1 a single passage communicating witheach of theinlet ports,--and"a vertical-portion, *intermediate the'endsof "the horizontal "portion, providing an intake passage communicatingwith the carburetor for themagine. As a result of theirregularfiringorderof 3 the cylinders-with the consequent necessityofsupplying'the combustible mixture first to one end it of the engine andthen-=to the opposite end, abovepointed out, there must be a constantreversal of the direction of flow of the combus- 5 'tible mixture in thehorizontal portion'ofcthe manifold. 'lhis' constant reversal of 1 thedirection of fiowsets up a turbulent condition within the manifold and.av surging :back and forth resulting lin a starving of some of thecylinders 40 with la consequent impairment of iefliciency of operation.Because of the setting up of different zpressures .at r the intakepassage, Lthis :lturbulent condition also results in an irregular demandon the: carburetor, thus varying the I: richnessro f 45 vthezmixturesupplied.

- to t is a general ob'ect :of :the invention, .therefare, to provide animproved intake manifold :of novel .constructionceliminating the surgingand turbulent condition :heretof ore existing ainzmanip @1 folds 'toassure'fian' equal supply of combustible :mixture 8 to each oflthecylinders and axmixture or constant :richness r he invention. 'isxtoprovide "ansi intake'i manifold; nn which r-the combustible r mixtu're:hasnamniedirectional flow L-therebyI to k uNrrEos rAres PATENT OFFICE1934,."Serial No. 717,215

eliminate the turbulent condition in the manifold.

'Another' object of the. invention is to provide an intake manifoldhaving a common intake passage-atone 'endtand'a plurality of branchedpassages leading from'the'commo'n passage and eachbranch'communicating.successively with the intake ports-ofcylindersfiring in asequence correspondingitothe distance of theintakeports of the cylinders supplied by that branch away from thecommon passage. l i v Yet :another objectiof the invention is torprovidean intake manifold foruseon a six-cylinder enginehaving thecommon intakepassage at one fend andthree branch passages, each branchpassagesupp'lyingtwo cylinders'the ports of which are spaced? from thecommon passage 2. distance corresponding tothe'firing order of thecylinders, and the "branch passages communicating with the. commonpassage at points spaced from the carburetor distances inverselyproportional to the firing order of the cylinders supplied by therespective passages.

Other objects and advantages will becomeapparent from the following'detailed description taken in :connection with the accompanying drawing,inwhich: l

Fig. 1 is a sectional partially diagrammatic view of amanifold embodyingthe features of the invention.

"Fig.-2':is a diagrammatic view illustrating the firing order of asix-cylinder engine. M p

i While the invention-may, with slight modifica- .:tions,-be adapted foremployment with engines having varying numbers of cylindersgit is,forpurposes 'ofdisclosure, described and shown herein as adaptedfor useone. sixecylinder engine. It isto-beunderstood however, that theinvention :isnotto be limited to -the specific embodi- -ment shown butistoecover all modifications and :altern'ativeconstructions fallingwithin thespirit "and "scope of the invention as defined-by the appendedclaims.

I Astabove stated, the invention is herein shown as embodied inan intakemanifold designed for .use with a six-cylinder engine. Intake ports forthe cylinders are diagrammatically shown in the drawing and numberedconsecutively from I to 6 to correspond with the usual numbering of thecylinders. l l

.It is wellknown to those skilled in the-art that in six-cylinder,four-cycle internal combustion rengines each cylinder fires once inevery two revolutions of the: crankshaft. Thus successive ,cylindersfireat everyone-third'revolution of. the

10 circular diagram, Fig. 2, when traversed in a clockwise direction ofrotation.

bulent state of the combustible mixture with its 15 resultant starvingof certain cylinders 'andinef-' ficient operation. designed to produce asubstantially uni-directional fiow of the combustible mixture in which,the opening of a port gives to the mixturean, 20 impetus in the generaldirection of the subsequently opening porthGenerally speaking, thisuni-directional flow of the mixture is obtained by providing a manifoldhaving a large common intake passage and a plurality of smaller branch 2passages supplying one or more cylindersselected 30 passage 1 is locatedat one end of the manifold and has three branch passages 8, 9 and ex-.tending laterally therefrom in the same general direction. One end ofthe passage 1 has an opening II for communication with a carburetor, notshown, and the manifold is formed-at that end with a flange I2 by meansof which it may be secured to the carburetor. At the .end remote fromthe carburetor, the passage 1 merges gently into the branch passage 8which communicates in succession with the intake ports I and 5.Consideration of Fig. 2 will show that cylinder 5 fires a 120 crankshaftdegree interval after cyle inder I. As a result, opening of port I vandasuction of combustible mixture into the cylinder causes the combustiblemixture to have a movement along the passage 1 and the branch passage 8.The impetus thus given to the combustible mixture carries the same alongthe branch passage 8 so that a 120 crankshaft degree interval later,when the valve 5 opens, there is an ample supply of mixture availableforthat cylinder. I 4 1 Likewise branch passage 9 communicates insuccession with the intake ports of two cylinders in the order offiring, namely first with-port 3 and at the extreme end with-port 6.With this arrangement these ports are supplied without'a reversal of thedirection of flow thus assuring an adequate supply of combustiblemixture. Thus, the flow of combustible mixture" upwardly in the passageI started by the opening of ports I and 5 aids in assuringanadequatesupply for port 3, while the impetus along the branch 9 givento the mixture by the opening of port" 3 assures an adequate supply forthe remote port-6'. In like manner, branch passage-l0 communicates withports 2 and I which correspond in remoteness from the common passage 1to the firing order of thecorresponding cylinders.

Branch passage III communicates with the common passage I immediatelyadjacentthe carburetor while passage 9 communicates at a pointintermediate the passages 8 and lfl's lt'will be noted that port 3,supplied by branch passage 9, opens a-120 crankshaft degreeintervalafter port To that end the manifold is 5, supplied by branch 8, and thatport 2, supplied by branch passage I 0, opens a 120 crankshaft degreeinterval after port 6, supplied by branch passage 9. ,This arrangementfurther adds to the perfection of uni-directional flow obtained for notonly are the ports in any one branch arranged to assure uniform flow butthe several branches are also arranged so that there is no reversal -ofdirection of flow in the passage 1. Thus'it will be seen that the branchpassages 8,

9 and Ill draw combustible mixture from the The invention contemplatesthe perfection of an intake manifold free of a surging and turfcommonpassage in the order named.

It is believed apparent from the foregoing description that by providinga suitable number of branch passages supplying one or more intake portsselected to be increasingly remote from a 'commonpassage in the order offiring of the cylinders they supply, the manifold may be adapted for usewith 4, 8 or any other number of cylinders. The manifold so designedwould have the same uni-directional flow with a resultant uniform supplyof combustible mixture to each of the cylinders and uniform andefficient operation.

1 claim as my invention:

1. An intake manifold for a multi-cylinder internal combustion enginehaving a common intake passage located at one end and a plurality ofbranch passages communicating at one end with said common passage andextending laterally therefrom in the same general direction, each ofsaid branch passages communicating with at least one cylinder, and theintake ports of the cylinders supplied by any one branch passage locatedat relatively greater distances along the branch passage away. from thecommon passage in the order of firing of the cylinders supplied.

7 2'. An intake manifold for a 'multi-cylinder internal combustionengine having a common intake passage located at one end and a pluralityof branch passages communicating at one end with said common passage andextending laterally therefrom in the same general direction, each ofsaid branch passages communicating in succession progressively away fromthe common passage with the intake ports of cylinders firing in a.sequence corresponding to the relative distance of their intake portaway from the common passageto obtain a unidirectional flow ofcombustible mixture in the passages of the manifold.

my 3. An intake manifold for a multi-cylinder internal combustion enginehaving a common intake passage and a plurality of branch passagescommunicating at. one end with said common passage and extending insubstantially the same direction therefrom, each branchvpassagecommunicating with cylinders the intake ports of which are locatedincreasingly remote from the common passage in the order of firing ofthe cylinderssupplied by the respective branch passages. Y 4. An intakemanifold for a multi-cylinder internal combustion engine having. acommon in.- take passage located atone end and a plurality of branchpassages communicating at one end with said common passage and with aplurality of cyl- 'inder'-intakeports of such engine, said branchpassages extending substantially in the same direction from said commonpassage.

v5. An intake manifold for a multi-cylinder internal combustion enginehaving a common intake passage and a plurality of branch passagesleading substantially'in the same direction fromthe common passage andcommunicating respectively with-the intake ports. of such cylinderswhereby.

opening of a port for the intake of combustible mixture through one ofsaid branch passages gives to the combustible mixture in such branchpassage an impetus in the general direction of the intake port of acylinder next in firing order.

6. An intake manifold for a six cylinder internal combustion engine witha 1536--2-4- firing order having a common intake. passage at one end forcommunication with a carburetor, a first branch passage leading fromsaid common passage and communicating in succession with the intakeports of cylinders I and 5, a second branch passage leading from saidcommon passage and communicating in succession with the intake ports ofcylinders 3 and 6 and a third branch passage leading from said commonpassage and communicating with the intake ports of cylinders 2 and 4,said branch passages communicating with said common passageprogressively toward the carburetor in the order of their numbering.

'7. An intake manifold for a six-cylinder internal combustion enginehaving a common intake passage at one end for communication with asource of combustible mixture, at first branch passage supplying twocylinders and communicating with the common passage at the end remotefrom the source of supply, a second branch passage also supplying twocylinders and communicating with the common passage intermediate itsends and a third branch passage supplying the remaining two cylindersand communicating with the common passage adjacent the source of supply,the cylinders supplied by any one passage firing in immediate sequencewith the intake port of the first cylinder to fire nearest the commonpassage, and the cylinders in the several branch passages firing in thesequence of the numbering of the branch passages.

8. An intake manifold for a six-cylinder internal combustion enginehaving a common intake passage at one end and three branch passagesextending from said common passage in substantially the same generaldirection, each branch passage communicating with two cylinders, the

inlet ports of which are located at relatively greater distances fromthe common passage corresponding to the firing order of the cylinderssuplied. p 9. An intake manifold for a multi-cylinder internalcombustion engine having a common intake passage at one end forcommunication with a carburetor and a plurality of branch passagesleading from said common passage, each of said branch passagescommunicating successively in progression away from said common passagewith the inlet ports of a group of cylinders in the order of firing ofthe individual cylinders in such group and said branch passagescommunicating with said common passage in progression away from thecarburetor in reverse order of the firing of the groups of suchcylinders.

10. For use with a multi-cylinder internal combustion engine, a manifoldhaving an intake passage and a plurality of branch passages leading inthe same general direction from such intake passage, each branch passagehaving outlets for communication with a plurality of cylinders of saidengine, the outlets of each branch bein at different distances from theinlet passage and in accordance with the firing order of the cylindersfor their communication.

11. An intake manifold comprising a vertically disposed mixing chamberatan end thereof, a fuel distribution passage extending laterally fromsaid mixing chamber, and other fuel distribution passages respectivelyabove and below the first named passage, all of said passages beingsubstantially in the same vertical plane, there being a plurality ofdischarge openings in certain of said passages, and the dischargeopenings in each of said certain passages being spaced at varyingselected distances from the mixing chamber.

12. For use with a multi-cylinder internal combustion engine, a manifoldhaving a fuel passage and a plurality of distributive passages extendingcommunicatively from such fuel passage, certainof said distributivepassages having outlets for communication with a plurality of cylindersof said engine, the respective outlets of each of said certaindistributive passages being at different distances from the inletpassage, such distances being in accordance with the firing order of thecylinders for such outlets.

13. An intake manifold for an internal combustion engine havingcylinders fired in an order selected for preserving the equilibrium ofsuch engine, said manifold comprising a common intake passage having anintake opening, and a plurality of branch passages communicating at anend with said common passage and extending in substantially the samedirection from said passage, certain of said branch passages beingadapted to communicate with a plurality of said cylinders, the cylindersfor respective communication with a branch passage having a successivecharging sequence without the intervention of charging of othercylinders thus causing prolonged periodic fuel movement in such branchpassages, and the branch passages communicating with said intake passageat selectively different distances from said intake opening according tothe order of such periodic fuel movement therein.

14. The combination with an internal combustion engine having cylindersin which are reciprocated pistons in an order selected for minimizingengine vibrations, of an intake manifold comprising a common intakepassage having an intake opening, and a plurality branch passagecommunicating at an end with said common passage, certain of said branchpassages being adapted to communicate with a plurality of saidcylinders, and the cylinders for respective communication with each ofsaid certain passages having fuel intake periods overlapping in timethus causing prolonged periodic fuel movement in such branch passages,and the branch passages communicating with said in- [take passages atselectively different distances from said opening according to the orderof such periodic fuel movements therein.

15. An intake manifold as set out in claim 14, but wherein said branchpassages extend substantially in the same direction from said commonpassage.

BENJAMIN ARTHUR SWENNES.

